The present invention relates to cutting blades for cutting sheet wrapping materials. More specifically, the present invention relates to cutting blades used to sever plastic film or other sheet wrapping material that is dispensed from a roll package.
Plastic film or other sheet wrapping material is widely used throughout the food industry to wrap or cover various food products. The plastic film or other sheet wrapping material is typically dispensed from a roll contained in a box. Whenever a piece of plastic film or other sheet wrapping material is required, the length of the plastic film or other sheet wrapping material is withdrawn from the box and cut to length by a cutting blade that is attached to the front panel of the box.
The cutting blade commonly used for many years has been a thin metallic saw-toothed blade having cutting points extending along the exposed edge of the blade. Although the points of the cutting blade can nick or cut the user, the real risk to the user results from the cutting blade being made from a thin strip of metal. Just as a piece of paper can cause a cut, the edge of a thin strip of metal, with or without saw-toothed points, can cut. Any exposed edge of the metal strip presents a hazard.
The cutting blades illustrated in my earlier patents (identified above) reduced the risk of injury from the teeth and/or paper cuts from the free edges of the cutter strip.
Cutting blades in the shape illustrated in FIG. 10 of my U.S. Pat. No. 5,947,360 are mass produced as individual pieces, bulk packed and shipped to the manufacturer of plastic film packaged products. This latter manufacturer must remove an individual blade from the bulk shipping container and assemble it to, or loosely deposit it in, the box holding the film. In the shipping container, the prior blades tend to nest or become interlocked with each other and must be manually separated prior to putting them in or on the box.
In the present invention, a cutting blade for cutting plastic film or other sheet wrapping material is provided which not only reduces the risk of inadvertent cuts to the users or other handlers of the blade but also prevents nesting or interlocking of the blades when they are packed in bulk for shipment to the manufacturer.
The cutting blade may be engaged on the box during completion of the packaging operation by the manufacturer of the wrapping material, or may be deposited in the box by the manufacturer, and thereafter be engaged on the box by the user. The cutting blade allows a user to withdraw a length of sheet wrapping material, such as plastic film material from the box, and cut the sheet wrapping material to length without serious risk of injury to the user. The cutting blade has two parallel longitudinally elongated shoulders connected by a web having a central portion in the form of a substantially flat surface. The longitudinally-elongated shoulders comprise arcuate shoulders extending along the opposite sides of the central portion, and a row of teeth project from the flat surface midway between the sides, so that the row of teeth is parallel to the shoulders and projects upwardly between the shoulders.
The teeth are limited in height and in the preferred embodiment are positioned with roots substantially in the plane of the flat surface, and tips projecting above the plane by a small fraction of the width of the web between its elongated shoulders. The limited projection of the teeth above the plane of the web reduces the ability of the tips to inadvertently cut the user.